Normally, wind turbines are erected in places in which the wind conditions are advantageous, for example, in places with few obstacles blocking or altering the path of the wind. This means that the wind turbines often are positioned in more or less remote places with a poor infrastructure such as in terms of road quality.
This creates some problems in relation to the necessary maintenance of the outer components of the wind turbines, such as the wind turbine blades or the surface of the wind turbine tower. The magnitude of the problems has accumulated significantly in recent years with the increasing size of the wind turbines.
Previously, freestanding cranes or lifts have been used in connection with maintenance or reparation of the outer components of the wind turbines. However, with the poor infrastructure, the transportation of the cranes or lifts to the erection places of the wind turbines is somewhat costly and time consuming.
In order to overcome the problem of transporting large and heavy equipment to the erection places, different solutions have been suggested.
One has been using persons lowering themselves down the side of the wind turbine tower or blades using ropes connected to the nacelle. However, the method naturally requires experts in climbing and is somewhat restricted in the work possibilities on the wind turbine, and as such is not a feasible solution to the problems of maintenance or reparation of the outer components of the wind turbines.
Another has been the installation of a crane and a cable basket underneath the nacelle of the wind turbine, allowing the basket to be lowered down the side of the wind turbine. However, the basket is difficult to position correctly and difficult to work from due to its unstable nature.
The invention establishes a method and system for wind turbines without the above-mentioned disadvantage.
The invention creates a method and system which allow one or more workers to be positioned at any adjacent position outside the wind turbine such as near one of the wind turbine blades without involving heavy equipment on the ground.
Further, the invention creates a method and system which allow safe and stable conditions for the workers.